1. Field Of The Invention
This invention relates to burner nozzles for burning petroleum products during well testing, and more particularly, to a burner nozzle with a replaceable annular air jet and an oil swirl chamber which is clamped in position such that it is always in compression.
2. Description Of The Prior Art
Burner nozzles in which petroleum products are burned, and in particular to dispose of the products of oil well testing, are well known. U.S. Pat. No. 4,011,995 to Krause discloses a nozzle with petroleum products and air mixed by the nozzle to facilitate burning of the petroleum products. In this device, it is possible for oil to be forced under pressure into the air can or jacket and into the air supply line in the event of rupture of the oil line, an undesirable situation.
U.S. Pat. No. 4,664,619 to Johnson et al. discloses a burner nozzle for mixing petroleum products to be burned with air in which air is injected into a petroleum stream, exiting an oil orifice, from an air jacket or can which is spaced from the oil orifice and its petroleum product supply line such that any leakage of petroleum is directed into a space between the supply line and the air jacket so that the petroleum products cannot be forced under pressure into the air jacket. This burner nozzle utilizes an oil swirl chamber with the oil orifice integral therewith and which is attached to an oil conduit such as by welding. A plurality of air exit holes are defined in a spacer at an end of the air jacket adjacent to the oil orifice. The air exit holes direct air from an annulus in the air jacket into the oil stream. These air jets serve to atomize the oil stream to facilitate burning.
A problem with the prior burner nozzle of Johnson et al. is that the air stream from each of the jets tends to spread the further the air stream is from the nozzle, and this can be so great that the air velocity is reduced sufficiently so that it does not properly atomize the oil stream when it impinges the oil stream. Another problem is that the individual jets do not atomize the oil stream around the complete circumference thereof because the air is jetted from individual holes. This leaves "fingers" of oil between the air jets which do not get atomized or agitated at all which has a detrimental effect on burning. The present invention solves this problem by providing an air jet defining an annular air orifice therein which provides an even stream of air around the circumference of the petroleum stream, thus insuring better atomization and more efficient burning. In one embodiment, the air stream is directed into the petroleum stream substantially simultaneously as the petroleum stream exits the petroleum orifice. This appears to be better for more viscous fluids and/or relatively low flow rates.
U.S. Pat. No 2,325,495 to Ferguson discloses an oil burner with an apparently annular air discharge opening adjacent to a burner tip. The air discharge opening is formed by an integral nozzle portion of an air pipe. The burner of Ferguson does not have a replaceable and interchangeable air jet as does the present invention.
Many apparatus of the prior art utilize welded components which are not easily replaced and which require expensive hardened materials. The present invention allows replacement of many of the components which are subjected to wear from either the petroleum stream or the air stream. The above-referenced patent to Ferguson has a swirl body which has a radially outwardly extending flange which is clamped between an end of an oil pipe and the burner tip. The main portion of the body extends from this flange and is unsupported. In particular, the swirl chamber used in the present invention is clamped on opposite ends so that it is always in compression which allows use of materials such as ceramics which provide long service life, but which cannot be used in situations where the components are welded or are in tension. No portion of the swirl chamber of the present invention extends unsupported as in the Ferguson apparatus, and thus the present swirl chamber is less subject to vibration and possible fatigue problems associated therewith.